In the manufacture of clothing it is often necessary to feed small sections or pieces of fabric, called fabric workpieces, into processing machines which edge, sew, and the like. For example, in making dungarees or jeans, the rear seat patch pockets will first be cut as rectangles or polygons of denim, and then singly fed to a machine for hemming the top edge (prior to sewing the patch onto the pants to form the pocket). Or, one leg piece will be fed to a machine for sewing on a fly zipper tape.
Typically fabric pieces will be simultaneously cut from multiple layers on a conventional cutting table, and arrive at the processing machine stacked. The stacks of fabric pieces cut in this manner typically have individual pieces which alternate side up and side down in the stack. Jeans fabric, for example, usually has a rough, dark side and a smooth, light side, and all the pieces must arrive at a sewing station with a proper side up if the assembled jeans are not to be defective.
In the manufacture of jeans, pieces like pocket patches, belt loops and fly material have traditionally been picked off from the stack manually and hand fed into the sewing or processing machine, because existing devices were unable to reliably perform the necessary operations, which are: first, picking up from the stack only the single top piece of fabric (to avoid feeding double pieces to the processing machinery); next, inspecting the pieces to determine which side is facing up; third, flipping those pieces which have the wrong side facing up; and, fourth feeding the individual pieces into the processing machine.
Thus, the need exists for an automated device which can automatically remove fabric parts one at a time from a stack of like parts which alternate side up and side down, determine which side is up, and direct each part through a feeding path or an inverting path so that when all parts arrive at a sewing station they have the desired side up.